Glycerol 3-phosphorylcholine (GPC) is a metabolite whose presence was only recently discovered in muscle tissue (Burt, et al., Biochemistry 15, 4850-4853, 1976). This research is designed to study the relation between GPC and such muscle disease as Duchenne dystrophy and myotonic dystrophy. I will use 31P nuclear magnetic resonance (nmr) to examine extracts from diseased and normal human muscles, genetic animal dystrophic muscles, and drug-induced animal dystrophic muscles. By quantitation of the GPC present, I should be able to help develop 31P nmr into a specific tool available to the diagnostician for clinical detection of human muscle disorders. Analysis of the extracts should additionally point to new directions in the search for etiology of these crippling and fatal muscle diseases. I wish to study the enzymes which control GPC concentration, that is lysophospholipase, which cleaves lysolecithin to GPC and a fatty acid, and GPC phosphodiesterase, which cleaves GPC to choline and alpha-glycerolphosphate. These enzymes appear not to have been examined in human tissue before. The activities will be measured in muscle homogenates and subcellular fractions by chemical, radiotracer and 31P nmr techniques. These experiments should answer whether the enzymes lysophospholipase and GPC-diesterase are involved in the primary defect of hereditary human muscular dystrophies.